Boiler



BOILER Filed June l, 1929 2 Sheets-Sheet l -h f /f/ v fr 4a. 3%

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Filed June l. 1929 w. A. .1.l KREAGER BOILER 2 Sheets-Sheet 2 PatentedNov. 3, 1931 UNITED STATES PATENT OFFICE 'WILLIAIVI A. J'. KREAGER, 0FDENVER, COLORADO, `.lsSiICrll'OR, BY MESNE ASSIGNMENTS, l

TO BARQUE ROYALTY, INC., OF DENVER, COLORADO, A CORPORATION OF COLORADOi f y BOILER.

Application ined .runeA 1,

This invention relatesv to improvements in boilers of the type employedin connection with the production of low pressure steam for heatingbuildings and for the production of hot water for use inhotwater heatingsystems and for similar purposes.

It is the obj ect of this invention to produce a boiler which shall beadapted to burn', either gas or liquid fuel and which shall be soconstructed that it will have a very large thermal eiiiciency so thatpractically all of the heat values of the fuel will be transferred tothe water. y

This invention, briefly described, consists in a boiler which hasbeenshown as formed by flat parallel sides or. ends Vthat are connected by asemi-circular top. Located within the boiler is a steel tube ofcylindrical shape which forms the combustion chamber and which issecured to Vone of the end plates ot the boiler. The inner end of thiscombustion chamber terminates in aheader from which a plurality of linesextend, parallel with the combustion chamber to a point near its otherend where they connect with an Aannular header. The linterior of thisheader is connected with a second header located below and from this theflue passages orthe combustion gases extend in a zigzag direction to theoutlet which is near vthe bottom of the boiler. The feed water isadmitted near the bottom so as to come in Contact with the flues nearthe point where the gases leave the boiler. i VThe water which entersnear the bottom of the boiler passes upwardly between and along the Huesand as it ascends, it absorbs heat from the hot vfines and is constantlycoming in Contact with heating surfaces of higher temperature. until itreaches the wall of the ceinlnistion chamber which, of course, is ofhigher temperature than' any of the fines. By the arrangement justdescribed, the feed water will come in contact Vwith the coldestfluesurfaces and will become gradually heated as it passes upwardly so asVto corne in-c mtact with. the more highly heated surfaces and in thismanner auniform temperature dient will be maintained between the Water.nd the heatingsurfacesthroilghout the boiler.

serial No. 367,665. y y f Fig. 2 is a section through the lower head-:

er, taken on line 2 2, Fig. l;

F ig. 3 is an endelevation of the boiler; and Fig. 4 is a section takenon line 4%4, Fig. l. In the drawings reference numeral l repreals 2and?) represent the sides. The rear end wall ofthe boiler has beenindicated by reference numeral 4. VThe front of the boiler instead ofbeing made from a single plate,

is made fromthree separate plates which .g lhave been designated bynumerals 5, 6 and 7; In the construction of the boiler forming thesubject matter of this application, the

several plates were electrically welded and the drawings have thereforebeencross hatched so as to indicate a unitary'or integral construction.The sides 2 and 3 are connected by a semicirculardome 8 in ,they mannershown 1n Fig. 4. Extending transversely of the interior ofV the boilerare supporting` .bars 9, `whose ends are electrically welded to theYinside of the side walls.l A. narrow flat .plate 10 is supported on thetransverse bars 9 and servesV as a support for the combustion chamberand its associated headers and llues. .Y Upwardly extending arms 1l areintegrally secured to the transverse bars 9 and have'their upper. endsconnected by means of barslQ, which cooperate with the plate ll() toform a cradle or rest for the combustion chamber and associated parts ina manner which will-be described and which is a-pparentvfrom thedrawings. The combustion chamber fis formed from an elon- .gatedcylinder 13. which extends inwardly `through-a bole inthe plate 5 andwhich .eloctricallyor otherwise autogenmisly welded thereto. Secured tothe inner end of the cylinder 13 is a header 14 that is welded to thecylinder. A substantially annular header 15 enclcses the cylinder 13 butis not sents the bottom of the boiler, while nuiner- CTX connected withthe latter. Flues 16 connect the interiors of headers 14 and 15 in themanner shown. Located below the transverse bars 9 is a header 17 whichis preferably formed from cast iron and which is provided with threecylindrical projections 18 near its top and two similar cylindricalprojections 19 near its bottom. These projections extend throughopenings in the plate 7 and are welded to the latter. The rear wall 20of the header 17 is provided with four rows of openings for thereception of flues 21. The two center rows are enclosed by a curved wall22 which divides the interior of the header into three compartments inthe manner shown in Fig. 1. The other ends of flues 21 extend throughopenings in the plate 23 and are welded to the latter. Curved walls 24form with the plate 23 two chambers the upper of which receives theinner ends of the two upper rows of tubes while the lower chamber is incommunication with the two lower rows of tubes. The header 15 isprovided with three tubes 25 which extend through openings in plate 5and are welded to this plate. Secured to the outer ends of these tubesare elbows 26. Similar elbows are connected with the tubular members 18and these elbows are joined by means of pipes 27.

In the drawings the burner has been indicated by reference numeral 28and the products of combustion pass inwardly through the combustionchamber and thence flow through the flues 16 into the interior of theheader 15 and thence through pipes 27 to the upper chamber of header 17from which they flow through the upper row of tubes 21 to the interiorof the upper chamber on plate 23 and return thence through the secondrow of tubes into the central chamber formed b v the walls 22, from herethe gases flow through the third row of tubes to the lower chamber onplate 23 from which they return through the lowermost row of tubes tothe lowermost chamber in header 17. from whence they pass outwardlythrough tubes 19 into a pipe which extends to the outside of thebuilding. lt will be seen from the above description that the flue gasesflow downwardly and are discharged near the bottom of the boiler, whilethe water enters the boiler and Hows upwardly. It will also be seen thatthe combustion chamber and flues are entirely surrounded by water andthat the water enters at the point where the Hue gases leave andtherefore there is a gradual increase in the temperature of the waterfrom the bottom towards the top so that the temperature of the watervaries in the same direction as the temperature of the flue gases andtherefore as the water iov-es upwardly and becomes hotter it iscontinually coming in contact with surfaces that are heated to a highertemperature. After the boiler has been started in operation and the feedwater supply adjusted so as to replace the water that is vaporated, theinterior of the boiler will soon come to a substantially stationaryposition so far as temperatures are concerned and the temperature of thewater and of the iue gases will remain the same at all points andtherefore there will be no violent fluctuations in temperature and as aconsequence no corresponding changes in expansion and contraction andtherefore the boiler is subjected to less strain than it would be if thefeed water were introduced periodically at or near the top of theboiler.

I want to call attention to the fact that the cylindrical combustionchamber is connected to the boiler at one end only, and that themanifold 14 rests on the upper surface of the plate 10 so that it canfreely expand and contract in accordance with the temperature variationsto which it must necessarily be subjected. Since the cylinder 13 and theiiue 1G are made of the same kind of material, they have the samecoefficient of expansion and therefore it is possible to weld thetubular members 25 to plate 7 without setting up any severe strains dueto the expansion and contraction. The end of member 1?) is closed by aplate 29 which is held in place by means of bolts 30. The boiler isprovided with scveral openings one of which has been designated byreference numeral 31 and which serves as the discharge for steam or hotwater, while openings 32 and 33 are usually plugged but can be usedwhenever desired. The feed water opening has been indicated by referencenumeral 34.

.Vhen oil is employed as fuel, it can be preheated by passing it througha chamber 35 that is in communication with the outer surface of one ofthe pipes 27. The pipe 27 can either be enclosed by means of a pipe 36of bigger diameter so as to form an annular chamber through which theoil may pass, or a flexible copper tube 37 may be wrapped. around thispipe and in this manner the oil can be raised to a high temperaturebefore it enters the burner, thereby facilitating the production ofvapors.

From the above description it will be apparent that 1 have produced aboiler which is especially well adapted for use in connection with lowpressures and which is so constructed that a very high thermalefficiency can be attained. The boiler is intended for use withapparatus producing a forced draft and this makes it possible to havethe products of combustion travel downwardly and to have them dischargedfrom the boiler near the bottom thereof. ed surfaces a re covered withwater and there fore very little. if any, of the heat hrs an opportunityof escaping. The outside of the boiler can. of course, be covered with alayer of heat insulating material as to keep the Practically all theheatlossdue to radiation at the lowest point.

I-Iaving described the invention what is claimed as new is:

l. A boiler having' a tubular combustion chamber extending inwardly fromthe front end thereof, and terminating in a header located near the rearof the boiler, a hollow annular header surrounding the combustionchamber near the front end of the boiler, a plurality of lues connectingthe interiors of the headers, a header located beneath each of the othertwo. the one located beneath the annular header having a plurality ofseparate compartments and the one located beneath the rearmost upperheader having one compartment less than the front lower header, finesinterconnecting the compartments in the lower headers so that Hue gaseswill pass successively through all of the compartments, means forconnecting the interior of the annular header with the upper compartmentof the lower front header, yand means for connecting the lowercompartment of the possible last named header with a flue gas outletpipe located outside of the boiler.

2. A boiler having a tubular combustion chamber extending inwardly fromthe front end thereof and terminating in a header located near the rearof the boiler, an annular header surrounding the combustion chamber nearits front end, a pluralitv of ilues connecting the headers, a headerlocated below each of the other two, the one located near the fronthaving an upper, a central and a bottom compartment, the one locatednear the rear having an upper and a lower compartment, Hues connectingthe upper compartment of the rear header with the upper and the centralcompartment of the three compartment headerq and oth er fines connectingthe lower compartment of the rear lower header with the central andlower compartments of the three compartment' hea der, means forconnecting the interior of the annular header with the upper compartmentof the three compartment header, and means for connecting the lowermostcompartment of the three compartment header with a flue gas outlet pipelocated on the outside of the boiler.

3. A boiler having a plurality of transverse bars adapted to support acombustion chamber', a cylindrical combustion chamber located in theboiler above the supports, the inner end of the combustion chamberterminating within the boiler and having attached to its a header, aheader located near the front end of the combustion chamber fluesextending between and connecting the interiors of said headers, a headerlocated beneath each of the headers mentioned above, means forconnecting the interiors of the headers near the front end of the boilerwith each other WILLIAM A. J. KREAGER.

